v4l2vda: remove invalid DCHECK

With recent change [1] to use visible size instead of
coded size for the picture buffers, the DCHECK to ensure
picture buffer size and egl_image_size_ to be the same
is no longer valid. Since |egl_image_size_| is the coded
size, which can be different from visible size. So remove
the DCHECK.

[1] https://chromium-review.googlesource.com/c/chromium/src/+/2122484

Bug: b/153606160
Test: Verify no DCHECK on Cast display device when using V4l2VDA
Change-Id: I83772e29d8f21e0b3afece1fa9970d3c100fdc78
Fixed: 2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2143491Reviewed-by: Andres Calderon Jaramillo <andrescj@chromium.org>
Reviewed-by: Dan Sanders <sandersd@chromium.org>
Reviewed-by: Alexandre Courbot <acourbot@chromium.org>
Commit-Queue: Peter Qiu <zqiu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#758715}

media/gpu/v4l2/v4l2_video_decode_accelerator.cc

@@ -419,8 +419,6 @@ void V4L2VideoDecodeAccelerator::AssignPictureBuffersTask(
   for (auto&& buffer : v4l2_buffers) {
     const int i = buffer.BufferId();
 
-    DCHECK(buffers[i].size() == egl_image_size_);
-
     OutputRecord& output_record = output_buffer_map_[i];
     DCHECK_EQ(output_record.egl_image, EGL_NO_IMAGE_KHR);
     DCHECK_EQ(output_record.picture_id, -1);